Course Profile   Science, Grade 10, Locally Developed

 

Unit 2:  Chemistry: Chemical Reactions and their Practical Applications

Time:  29 hours

 

Activity 1 | Activity 2 | Activity 3

Unit Description

Students investigate, through laboratory experiments, a variety of chemical reactions with an emphasis on the use of household and workplace chemicals and practical applications of their reactions. Acids and bases are studied in detail to provide knowledge about their properties and uses. Students demonstrate their understanding of the pH scale to identify acidic and basic properties of materials. Students are given opportunities to demonstrate the proper storage, handling, and disposal of chemicals and the products of reactions. Safety, inquiry skills, collaboration, and communication are emphasized in this unit.

Strand(s) and Expectations

Strand(s):  Chemistry

Overall Expectations:  CHV.01, CHV.02, CHV.03.

Specific Expectations:  CH1.01-.08, CH2.01 A/B/C/D/E/F/G, CH3.01-.03.

Activity Title (Times + Sequence)

Activity 1

Characteristics of Chemical Reactions

630 minutes

Activity 2

Acids and Bases

690 minutes

Activity 3

Chemistry in Our Everyday Lives

420 minutes

Task Titles (Types, Times + Sequence)

Task

Type

Title

Time

1.1

Learning/Explore

Introduction to Lab Safety

45 minutes

1.2

Learning/Focus

Introduction to Lab Procedures

60 minutes

1.3

Learning/Diagnostic

Physical vs. Chemical Change Concept Attainment

30 minutes

1.4

Assessment

Physical Change vs. Chemical Change Checklist

30 minutes

1.5

Learning/Observe

Observing and Recording Characteristics of Chemical Reactions

60 minutes

1.6

Assessment

Chemical Reactions: Concept Mapping

30 minutes

1.7

Learning/Diagnostic

Cut and Paste Activity – Reactants and Products

60 minutes

1.8

Learning/Diagnostic

Factors that Affect Reaction Rates

60 minutes

1.9

Assessment

Rates of Chemical Reactions

45 minutes

1.10

Diagnostic

Identifying Everyday Chemical Reactions

30 minutes

1.11

Assessment

Chemical Reactions in the Real World

60 minutes

1.12

Summative Assessment

Station-Based Activity

120 minutes

2.1

Learning/Focus

Introduction to Acids and Bases

60 minutes

2.2

Learning/Diagnostic

Sour vs. Bitter

60 minutes

2.3

Learning/Diagnostic

Properties of Acids and Bases

60 minutes

2.4

Learning/Consolidate

Acid/Base Discussion and Note Taking

30 minutes

2.5

Learning/Focus

What is a Chemical Formula?

30 minutes

2.6

Learning/Focus

The pH Scale

30 minutes

2.7

Learning/Apply

Testing For Acids and Bases in Ten Consumer Products

60 minutes

2.8

Assessment

pH Determination of Acids and Bases

60 minutes

2.9

Learning/Assessment

Neutralizing Acids

60 minutes

2.10

Learning/Diagnostic

What is a Salt?

60 minutes

2.11

Assessment

Acid Rain

60 minutes

2.12

Summative Assessment

Acid Rain Research Paper

120 minutes

3.1

Learning/Explore, apply

Chemistry In Everyday Life

30 minutes

3.2

Assessment

Chemical Reactions in Life

30 minutes

3.3

Learning/Apply

Classification of Household Products

30 minutes

3.4

Assessment

Acid, Base, or Salt?

30 minutes

3.5

Learning/Consolidate

Guest Speaker

60 minutes

3.6

Assessment

Careers in Chemistry

45 minutes

3.7

Assessment

Safety Poster

75 minutes

3.8

Learning/Explore

Introduction to Environmental Chemistry

30 minutes

3.9

Learning/Assessment

A Closer Look at the Environment

30 minutes

3.10

Summative Assessment

Chemistry and the Environment

60 minutes

Prior Learning Required

The use of equipment, safe laboratory practices, and information learned about WHMIS in Grade 9 Science should be reviewed. Concepts dealing with physical and chemical changes are required from Grade 9 as well as a knowledge of elements and the Periodic Table.

Unit Planning Notes

Specific planning for each activity is described in the Teacher Facilitation section. However, the following preplanning would be helpful:

1.   Experiments in Activities 1 and 2 have extensive equipment requirements. Check each task carefully.

2.   Summative Station-Based Activity (Task 1.12) requires preplanning to assure that all required materials are available.

3.   Task 2.12 requires preparation of a research paper. Preplan with teacher/librarian and book access to the computer lab for access to the Internet.

4.   Guest speaker requires preplanning for Task 3.5.

5.   Tasks 3.6, 3.7, and 3.8 require preplanning with teacher/librarian or booking computer time to research on Internet.

6.   Please take note of safety guidelines for the chemicals used in the teacher facilitation and the Appendices (student worksheets).

Teaching/Learning Strategies

 

Strategy

Description

Activity 1

Concept attainment, concept mapping, inquiry/experimental

Concept attainment is used to help students to distinguish between chemical and physical change. Inquiry and experiments are used to further identify differences between the two changes. Factors affecting reaction rates are investigated through several experiments. The culminating Station-Based Activity involves both experiments and research.

Activity 2

Inquiry/experimental, discussion, research

Experiments are used to help students identify properties of acids and bases. Teacher-led discussion solidifies student knowledge. Inquiry is used to explore the properties of pH, neutralization, and salt production. Students conduct independent research into acid rain and its effect on the environment.

Activity 3

Inquiry/experimental, guest speaker, research

Students use knowledge from the previous activity and conduct experiments to identify substances as acids, bases, or salts. Use of a guest speaker explores the various options of careers in chemistry. Environmental chemistry becomes the focus of a research paper done by students.

Assessment and Evaluation

Task

Expectations

Tool

Assessing

Who

1.1

CH2.01A, CH2.01C

Worksheet Answer Key

Knowledge

Student

1.2

CH2.01A, CH2.01C

Worksheet Answer Key

Lab Safety Checklist Lab Procedures Rubric

Knowledge,

Inquiry

Teacher

1.3

CH1.01, CH2.01F

Worksheet Answer Key

Knowledge,

Communication

Teacher

1.4

CH1.01

Worksheet Answer Key

Knowledge,

Teacher

1.5

CH1.01, CH1.02, CH2.01A, CH2.01C, CH2.01F

Worksheet Answer Key Lab Safety Checklist

Lab Procedures Rubric

Knowledge,

Communication,

Inquiry

Teacher

1.6

CH1.02

Concept Map Checklist

Knowledge

Teacher

1.7

CH1.04

Worksheet Answer Key

Knowledge

Teacher

1.8

CH1.03, CH2.01A, CH2.01C, CH2.01F, CH2.01G

Worksheet Answer KeyLab Safety Checklist Lab Procedures Rubric

Knowledge,

Inquiry,

Communication

Teacher

1.9

CH1.03

SLL Rubric

Knowledge,

Teacher

1.10

CHV.01, CHV.02, CH3.01, CH3.02

Worksheet Answer Key

Knowledge,

Inquiry, Making Connection

Teacher

1.11

CHV.01, CHV.02, CH2.01F

Reading for Understanding Rubric

Knowledge, Communication

Teacher

1.12

CHV.02, CH1.01

Worksheet Answer Key

Knowledge,

Inquiry

Teacher

2.2

CH1.05, CH1.06

Worksheet Answer Key

Knowledge

Teacher

2.3

CH1.05, CH2.01A

Worksheet Answer Key

Knowledge, Inquiry

Teacher

2.4

CH1.05

No assessment

 

 

2.5

CH1.05

Worksheet Answer Key

Knowledge

Teacher

2.6

CH1.05, CH1.06

Worksheet Answer Key

Knowledge

Teacher

2.7

CH1.06, CH2.01A, CH2.01C, CH2.01F

Worksheet Answer Key Lab Safety Checklist

Lab Procedures Rubric

Knowledge,

Inquiry,

Communication

Teacher

2.8

CH1.06, CH1.07, CH2.01A, CH2.01C, CH2.01F

Worksheet Answer Key Lab Safety Checklist

Lab Procedures Rubric

Knowledge,

Inquiry,

Communication

Teacher

2.9

CH1.08, CH2.01A, CH2.01C, CH2.01F

Worksheet Answer Key Lab Safety Checklist

Lab Procedures Rubric

Knowledge,

Inquiry,

Communication

Teacher

2.10

CH1.08, CH2.01A, CH2.01C, CH2.01F

Worksheet Answer Key Lab Safety Checklist

Lab Procedures Rubric

Knowledge,

Inquiry,

Communication

Teacher

2.11

CH1.05, CH2.01F

Reading for Understanding Rubric

Knowledge, Communication

Teacher

2.12

CH1.05

Research Paper Rubric

Knowledge

Teacher

3.2

CHV.03

Comic Strip Checklist

Knowledge

Teacher

3.3

CH3.01

Worksheet Answer Key

Knowledge

Teacher

3.4

CH3.01

Worksheet Answer Key

Knowledge

Teacher

3.6

CH2.01D, CH2.01E, CH3.03

Teacher-created Checklist

Knowledge, Communication,

Making

Connections

Teacher

3.7

CH2.01D, CH2.01E, CH3.02, CH3.03

Poster and Presentation Rubric

Knowledge, Communication,

Making

Connections

Teacher

3.8

CH2.01D

Worksheet Answer Key

Knowledge

Teacher

3.9

CH2.01D, CH3.02

SLL Rubric

Knowledge,

Making

Connections

Teacher

3.10

CH2.01B, CH2.01D, CH2.01E

Research Paper Rubric

Knowledge, Communication

Teacher

Unit Resources

Print

Ritter, Bob, et al. Nelson Science 10. Toronto: ITP Nelson, 2000. ISBN 0-17-607501-1

Grace, Eric, et al. SCIENCEPOWER™ 10. Toronto: McGraw-Hill Ryerson Limited, 2000.
ISBN 007-560-363-2

Shapiro, B et al. Chemistry at Work. Pearson Education Canada, 1989. ISBN 0-7730-4730-1

Web Sites

ITP Nelson Website – http://www.nelson.com/nelson/science

Periodic Table Site – http://pearl1.lanl.gov/periodic/

Eisenhower National Clearinghouse – http://www.enc.org – Source of teaching resources

Canada’s Schoolnet – http://www.schoolnet.ca – Source of lesson plans, labs, demos, classroom activities, assessment tools, performance indicators and background resources.

See web sites identified in Unit 5 (Culminating Activity) dealing with acid rain.

Software

Encore Software. Science Advantage 2000: CD-ROM. Remedial. Provide interactive activities and self-paced study.

DK Multimedia: Super Tutor Learning Networks, High School Science-Chemistry, Biology, Physics: CD-ROM. Provided online homework help, lesson plans

Microsoft: Microsoft Encarta Deluxe 2000. CD-ROM. Current information source.

Audio Visual

Bill Nye Video – Acids and Bases (available at most School Board Resource Centres) or from Magic Lantern Communications, 10 Meteor Dr., Toronto, ON M9W 1A1
1(800)263-1717; e-mail – video@magiclantern.ca; web site – www.cbc.ca

(Teachers are reminded to follow all copyright regulations when showing videos)

Activity 1:  Characteristics of Chemical Reactions

Time:  630 minutes

Description

Students demonstrate an understanding of chemical reactions through hands-on investigations of everyday chemicals in the home, lab, and workplace. These investigations also lead into lab activities that demonstrate the factors that can change the rates of reactions. The difference between chemical and physical changes is underlined through these investigations. Students also use word equations to describe the reactions covered in this activity. An emphasis is placed on lab safety, and the safe use of glassware, Bunsen burners, chemical usage, and the safe disposal and clean up of a lab.

Strand(s) and Expectations

Strand(s):  Chemistry

Overall Expectations

CHV.01 – demonstrate an understanding of chemical reactions;

CHV.02 – investigate reactions of different types of everyday chemicals.

Specific Expectations

CH1.01 – demonstrate an understanding of the differences between chemical and physical changes;

CH1.02 – describe the characteristics of simple chemical reactions (e.g., synthesis, decomposition, oxidation);

CH1.03 – identify the factors that can affect the rate of chemical reactions (e.g., temperature, surface area, concentration of chemicals...);

CH1.04 – demonstrate an understanding of chemical reactions using word equations;

CH2.01A – demonstrate knowledge of safety procedures when carrying out investigations in the laboratory using materials, tools and equipment to carry out chemical reactions (e.g., wear safety glasses, use care when heating materials, follow WHMIS guidelines and emergency procedures, use proper procedures for handling, storage and disposal of chemicals);

CH2.01C – demonstrate the skills required to investigate chemical reactions, using instruments, tools, and apparatus safely, accurately, and effectively (e.g., evaporating water in a neutralization reaction to recover salt; determining the properties of acids and bases; simple synthesis, decomposition and oxidation reactions);

CH2.01F – communicate scientific ideas, procedures, results, and conclusions about chemical reactions using appropriate language and formats (e.g., sharing in small groups, demonstrations, structured lab reports);

CH2.01G – investigate, by laboratory experiment or classroom demonstration, factors that can affect the rate at which chemical reactions occur.

Planning Notes

1.   Most experiments require general laboratory equipment, such as test tubes, beakers, retort stand and clamp, Bunsen burners, and graduated cylinders.

2.   Station-Based Activity (Task 1.12) involves 6 different stations. Check the requirements for each station carefully.

Equipment required for Task:

·         1.2 – mothballs, vinegar, baking soda

·         1.5 – ammonium chloride, baking soda, vinegar, magnesium ribbon, copper(II) sulfate, iron filings, phenolphthalein, calcium hydroxide, tarnished penny, table salt, sugar, sodium phosphate, silver nitrate

·         1.8 – vinegar, carbon (powdered form), corn starch (demonstration)

·         1.10 – chart paper, markers, various print sources dealing with different types of chemical reactions

·         1.11 – selected/adapted short articles that focus on the chemistry behind everyday chemical reactions in the real world

·         1.12 – copper(II) sulfate, sodium hydroxide, copper wire, silver nitrate, baking soda, vinegar, dilute (less than 0.01 M) hydrochloric acid, candle

Prior Learning Required

Safe lab practices and procedures are reviewed at the start of this activity. Building upon learning covered in the Grade 9 Essential Science document will lead the students into this activity. Students build upon the concepts covered when studying physical and chemical change and extend this knowledge to lab explorations that identify the characteristics of both chemical and physical reactions.

Teaching/Learning Strategies

1.1 Learning Task:  Introduction to Lab Safety

Students participate in a scavenger hunt activity focusing on the location and the functions of lab and safety equipment that they will be using throughout the course.

Teacher Facilitation

1.   Lead a class discussion on the types of lab facilities found throughout society (e.g., environmental, medical research, engineering, nutrition, quality control, applied research). Lead students in a discussion to develop a board chart of types of labs and investigations carried out in each (e.g., testing of pH of rainwater in an environmental lab; how fast metals rust in a quality control lab; fat content of foods in an applied research lab). Have students copy this table into their notebooks.

2.   Prepare a scavenger hunt recording worksheet so the students can clearly record the location and use of the lab and safety equipment. Appendix 2.1 provides a sample worksheet, which may be customized for your classroom/lab.

3.   Organize the scavenger hunt in which the students locate and record where equipment is located throughout the room. Display school lab and safety equipment and lead a discussion about their names, functions, and proper way to use them (e.g., hardware, glassware, safety goggles, eyewash station, broken glassware/solid waste containers, fire blanket).

Assessment

Students can self-assess and peer-assess the worksheet a using teacher-created answer key.

Accommodations

The function and proper use section of the scavenger hunt recording worksheet can be designed as a matching and/or describing exercise on the worksheet (e.g., table format) to accommodate for students with poor memory and/or literacy skills.

1.2 Learning Task:  Introduction to Lab Procedures

Students carry out a simple lab that will focus on lab procedures, correct equipment usage, safe handling of chemicals, and effective observation/recording skills. Students become familiar with following lab steps, equipment storage and use, safe handling of chemicals, and record their observations in prepared charts.

Teacher Facilitation

1.   Introduce to students the Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3).

2.   Lead students through “Fizzy Pop Lab” (Appendix 2.4) and familiarizing students with correct lab procedures.

[Note: The rising and falling of the mothballs in the baking soda and vinegar solution is attributed to the gas being evolved from the reaction. The bubbles rise to the surface, carring the mothballs with them; the bubbles are lost and the mothballs fall again. Emphasis should be placed on the fact that the gas evolved in the solution causes the “fizz” sound that is heard in the solution.]

Safety Precautions

Students must wear safety goggles throughout this lab activity. Waste liquid should be disposed of using a waste bottle. Glacial acetic acid should not be used for this, or any other activity, covered in this course outline. Use household vinegar as a substitute.

Use the following protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Follow federal, provincial, and local guidelines.

The following MSDS (Materials Safety Data Sheets) information is provided:

Vinegar: Do not use glacial acetic acid in this activity. Use household vinegar.

Napthalene (mothballs): Keep mothballs away from sources of heat. Use a waste disposal jar to dispose of used mothballs.

Assessment

Assess student work using a worksheet answer key. Assess lab work using Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3)

Accommodations

Enlarge print for students with poor vision. Use scribe and/or peer helper, tape recorder, or computer as an alternative to recording observations in this activity.

1.3 Learning/Diagnostic Task:  Physical vs. Chemical Change Concept Attainment

Students take part in a concept attainment or sorting activity on the concept of physical vs. chemical change and participate in a teacher-led discussion on the differences between the two types of changes. Students complete a worksheet on physical and chemical changes (Appendix 2.5).

Teacher Facilitation

1.   Develop the concept of physical and chemical change by providing students with pictures of both types of changes. Students sort these pictures into two categories: physical change and chemical change.

2.   Lead a discussion on the characteristics of physical and chemical change by asking the students to summarize the key points demonstrated in the sorting activity. [Note: Characteristics of physical change include: altering only the form of a substance; physical changes are reversible; changing of state, magnetizing, and dissolving are examples of physical change; the chemical composition of substances are not changed in physical changes. Characteristics of chemical change include: production of a new product; production of heat, light, gas, or precipitate; colour change.]

Assessment

Make diagnostic assessment using a teacher-created answer key.

Accommodations

Group work will facilitate the review of the concepts of physical and chemical changes. Use of chart paper, markers, and defined roles for the group members (scribe, idea producer), will collectively allow for quick review of the required concepts. Possible arrangement: Think/Pair/Share (Appendix OV-4) for students with weaker abilities.

1.4 Assessment Task:  Physical Change vs. Chemical Change Checklist

Students complete worksheet identifying physical and chemical changes.

Teacher Facilitation

1.   Prepare worksheet describing a variety of situations which students identify as either physical or chemical change and explain why (e.g., pulverizing stone is a physical change because the stone has not changed, it has become smaller pieces; baking bread is a chemical change because a new compound has formed. See Appendix 2.6.

2.   Clarify for the students the background of some of the changes with which they may be unfamiliar (e.g., dry cleaning, dry ice in water)

Assessment

Assess using a worksheet answer key.

Accommodations

Provide a peer helper/scribe to assist with writing.

1.5 Learning Task:  Observing and Recording Characteristics of Chemical Reactions

Students carry out a series of experiments and observe and record their characteristics in chart form.

Teacher Facilitation

1.   Prepare worksheet for experiment that identifies evidence of chemical change. See Appendix 2.7.

2.   Review Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3) and familiarize students with their use. Identify to the students the lab safety warnings that should be followed in this lab.

3.   Solutions of copper(II) sulfate, ammonium phosphate, silver nitrate and calcium hydroxide should be prepared ahead of time and should be ~0.01M

4.   Some of the reactions in the experiments described below may be classified as decomposition (the breakdown or destruction of a substance into simpler substances), synthesis (putting together or combining of two or more substances to form a more complicated substance) or oxidation (the linking of oxygen with another substance).

5.   Students carry out a series of experiments and obtain the following information:

a.   Ammonium chloride (1 g) in 1-2 cm of water in a test tube causes a significant decrease in temperature. [Note: Change in temperature occurs.]

b.   Copper(II) sulfate solution poured on iron filings causes an immediate change in the iron filings. The surface of the iron is replaced by copper. [Note: Colour change and temperature change occur.]

c.   Sprinkle a little table salt on a tarnished penny in a watch glass. Add enough vinegar to cover the coin, and let stand for one minute. Wash off and dry the penny. Students observe that the tarnish has been removed and bright, shiny penny is left. [Note: Colour change occurs.]

d.   Burn a small piece of magnesium. Do not look directly at magnesium while it is burning.
[Note: Heat, light, and gas are produced.]

e.   Baking soda is added to vinegar. [Note: Gas is produced.]

f.    Teacher Demonstration: Mix 1 mL of sugar and 1 mL of baking soda together. Heat the mixture in a test tube with a supporting test tube clamp/retort stand. Have students observe and record the reaction.

g.   Students conduct investigations where precipitates are formed. Students put a small amount of sodium phosphate (Na3PO4) into a test tube. Record the appearance of the sodium phosphate.

h.   Add silver nitrate (AgNO3) solution, drop by drop, to the test tube. The silver nitrate solution should be in dropping bottles. Record the appearance of silver nitrate.

i.    Record the number of drops needed to produce a white precipitate.

j.    Students obtain 2 mL of phenolphthalein and calcium hydroxide(aq) in separate test tubes. Record the appearance of the phenolphthalein and the calcium hydroxide(aq). Add the phenolphthalein to the calcium hydroxide and record the appearance of the precipitate in chart form. Students should be given the definition of a precipitate - a solid insoluble material that forms in a liquid as a result of a chemical reaction between two soluble substances.

Safety Precautions

The MSDS (Materials Safety Data Sheets) have provided the following information on the chemicals used in this experiment:

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

Ammonium chloride: Use microamounts when used. Dispose of ammonium chloride using a

waste disposal jar. [Note: Empty containers can have residues, gases, and mists and are subject to proper waste disposal.]

Calcium hydroxide: Use microamounts when using. Caustic irritant to eyes, skin, and respiratory tract. Use a waste disposal jar.

Copper(II) sulfate: May cause skin irritation. This substance has caused reproductive and fetal effects in animals. Use a waste disposal jar.

Magnesium: Do not look directly at burning magnesium. Ensure that the lab is well ventilated.

Phenolphthalein: Use microamounts when using. Use a waste disposal jar.

Silver nitrate: Use microamounts when using. Danger! Strong oxidizer! Contact with other materials may cause a fire. Causes skin burns. Use a waste disposal jar.

Sodium phosphate: Use microamounts when using. Use a waste disposal jar.

Assessment

Assess student work using a worksheet answer key. Assess lab work using Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3).

Accommodations

Allow more time for completion of experiment by students with poor motor skills.

1.6 Assessment Task:  Chemical Reactions: Concept Mapping

Students prepare a concept map with the central topic being chemical reactions. The connectors and descriptors are provided to facilitate the production of a complete concept map.

Teacher Facilitation

1.   Introduce the arrangement of a simple concept map using TV as an example. (See Appendix 2.8 – What is a Concept Map?). A concept map is a diagram that indicates the relationships between other concepts in a meaningful framework. See Appendix 2.9 for a more elaborate sample of what a concept map looks like.

2.   Provide the students with a prepared list of connectors and descriptors based upon the past tasks covered in this activity. Hand out a sheet of blank paper and have them complete a graphic organizer on chemical reactions.

3.   The framework of connectors and descriptors is as follows:

Descriptor

(Subordinate concepts)

Connector

(Statements which link the Descriptors)

reactants

involve

products

becoming

irreversible

are

heat production

and are characterized by (Used five times.)

light production

an example would be: (Used five times.)

gas production

produce

colour change

which have

precipitate forming

 

burning wood

 

baking soda and vinegar

 

[Note: Additional words may be added here.]

rusting metal

 

cigarette burning

 

sour milk

 

new substances

 

new properties

 

Assessment

Use the Concept Map Checklist (Appendix 2.10) to assess the completed Chemical Reactions concept map.

Accommodations

Students are provided with a peer helper to assist them in completing the concept map. A Shape Only concept map could also be provided to facilitate the end concept map as well.

1.7 Learning/Diagnostic Task:  Cut and Paste Activity – Reactants and Products

Students cut and paste reactants and products from past experiments and arrange the components into a table that is divided up into products and reactants. Reference for this activity is Task 1.5.

Teacher Facilitation

1.   Review with students the fact that reactants are what was started with and products are what is created or what the reactants become. Relating the reactants to the start and products to the finish is an effective analogy.

2.   Task 1.5 involved six specific experiments. The reactants and products for each are as follows:

Experiment

Reactants

Products

ammonium chloride + water

ammonium chloride(s) + water(aq)

ammonium chloride(aq)* + water + decrease in temperature

copper(II) sulfate + iron filings

copper(II) sulfate(aq) + iron filings (s)

iron sulfate(aq) + copper(s)

tarnished penny + salt + vinegar

tarnished penny + salt + vinegar

shiny penny + salt + vinegar

magnesium + oxygen

magnesium + oxygen + heat

magnesium oxide (white ash) + heat + light

baking soda + vinegar

baking soda + vinegar

baking soda(aq) + water + gas

sugar + baking soda

sugar + baking soda + heat

heat + light + gas

* (aq) refers to the fact that the material is dissolved in water – i.e., an aqueous solution

3.   Utilize Appendix 2.11 for the cut and paste activity.

Assessment

Assess student work using worksheet answer key.

Accommodations

Think/Pair/Share (Appendix OV-4) approach can be used to accommodate students having difficulty with the task, or those who missed the lab (Task 1.5).

1.8 Learning/Diagnostic Task:  Factors That Affect Reaction Rates

Students, working in pairs, observe and record the factors that affect reaction rates (dilution, surface area, and temperature).

Teacher Facilitation

1.   Introduce the activity by carrying out a teacher-led discussion on what a “rate” refers to in chemistry. An excellent demonstration is the use of corn starch. Corn starch will burn slowly when it is placed in a small pile on a fireproof pad. Sprinkling a small amount of the powder in a Bunsen burner flame shows in a spectacular fashion how chemicals, when subjected to different conditions, have different reaction rates.

2.   Prepare worksheet for dilution and surface area experiments (See Appendix 2.12). Worksheet will include space to record student observations.

3.   Gather material for experiments described below:

The Effect of Dilution – Vinegar/Baking Soda Experiment

1.   Students prepare four different dilutions of vinegar solutions. In four test tubes, place the following amounts of water and vinegar according to the table:

Tube No.

Volume

Water (mL)

Volume

Vinegar (mL)

Total Volume of Solution (mL)

Proportion of Vinegar

(or Concentration)

1

5

1

6

1/6 or 0.17

2

11

1

12

1/12 or 0.083

3

17

1

18

1/18 or 0.055

4

23

1

24

1/24 or 0.042

      Place a stopper in each test tube and invert it to mix the water and vinegar.

2.   Students obtain four 50 mL beakers and place 1 g of baking soda in each beaker.

3.   Students observe and time how long each reaction carries through as the different concentrations of vinegar are added to their baking soda samples.

4.   Graph the results using a spreadsheet with Concentration of Vinegar on the x-axis (most to least concentrated) and Time (seconds) on the y-axis. Examples of graphing programs that could be utilized are: Excel, Appleworks, Corel Quattro Pro, or Microsoft 2.0. Each program has a tutorial to guide students in producing spreadsheets.

The Effect of Surface Area on Rates of Reaction

1.   Students obtain a small amount of powdered carbon and heat the sample in a deflagrating spoon in a Bunsen burner flame. Observations are recorded in chart form.

2.   Students obtain a small amount of powdered carbon and sprinkle the carbon into the flame. Observations will be recorded in chart form.

3.   Relating this experiment to the “sparklers” that are used during Canada’s Birthday will be an easy connection.

The Effect of Temperature on Rates of Reaction

1.   Students obtain a small amount of sugar and place it in a glass evaporating dish. Observations of the appearance of the sugar are made in chart form.

2.   Students transfer the sugar sample to a deflagrating spoon. A Bunsen burner is lit according lab safety protocol. The deflagrating spoon with the sugar sample is placed in the flame and observations are made in chart form.

3.   Relating how temperature increases the breakdown of sugar can be made using a comparison of the observations that are made in chart form.

Safety Precautions

Use a small amount of corn starch and utilize a fume hood so as to prevent contamination of the lab. Students must follow safe lab procedures when using the Bunsen burners.

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling

Disposal: Refer to federal, provincial and local guidelines.

The following MSDS information is provided:

Corn starch: Use microamounts when carrying out the demonstration. Use a fume hood to eliminate dust contamination.

Vinegar: Do not use glacial acetic acid for this activity. Use household vinegar. Vinegar can be flushed down the drain with excess water.

Baking soda: Use microamounts when using. This chemical released into the environment will not have a significant impact.

Carbon: Use carbon in a well-ventilated area. Use protective equipment as indicated. Sweep up material and place in a suitable disposal container if spilled.

Assessment

Diagnostic assessment using worksheet answer key. Assess lab work using Lab Procedures Rubric (Appendix 2.3) and Lab Safety Checklist (Appendix 2.2).

Accommodations

Pair students with appropriate ability level. Use peer helpers when available.

1.9 Assessment Task:  Rates of Chemical Reactions

Students complete a Science Learning Log (SLL) entry using directed vocabulary from past activities and experiments involving Rates of Chemical Reactions.

Teacher Facilitation

1.   Prepare a Science Learning Log worksheet with vocabulary (concentration, surface area, product, reactant, temperature) and focus questions (e.g., “How does the speed of a reaction change as the concentration increases?....temperature increases?...surface area increases..?”) Assign connections questions (e.g., “Why does food cook faster at higher temperatures?” of “If you want to cook pasta faster, would you use a big pot or a small pot?”).

Assessment

Assess SLL entry using SLL Rubric (Appendix OV-3).

Accommodations

Provide a peer helper to assist in completion of SLL entry. Allow students to dictate responses to a scribe or tape recorder.

1.10 Diagnostic Task:  Identifying Everyday Chemical Reactions

Using printed media sources (magazines, newspapers, etc.) students brainstorm and record in chart form, different types of chemical reactions.

Teacher Facilitation

1.   Place students in groups of three and provide chart paper and markers for recording their examples.

2.   Teacher or students collect pictures or old magazines and choose pictures for the activity.

3.   One student is recorder, one cuts out pictures of chemical change, and the third student brainstorms examples of chemical change.

4.   Outline the five characteristics of a chemical reaction to aid in this assignment.
[Note: Characteristics of chemical change are: heat given off, light produced, colour change, gas production, and formation of a precipitate.]

5.   The framework of the chart will be as follows:

Real World Area

Reaction

Cleaning

 

Hospital

 

Auto Repair Garage

 

Restaurant

 

Logging

 

[Note: Additional examples may be added here.]

Cook

 

Painter

 

Custodian

 

 

6.   Chemical reaction examples should be characterized by simple terms. See Activity 1.5 for definitions of decomposition, synthesis, and oxidation. Clearly identifying the products and the reactants is not necessary.

Assessment

Diagnostic assessment using worksheet answer key.

Accommodations

Arrange group members so that mix is appropriate to the ability level of the students.

1.11 Assessment Task:  Chemical Reactions in the Real World

Students select a reading article and answer specific questions on the chemistry behind everyday reactions in the real world.

Teacher Facilitation

1.   Select/adapt several articles (see Appendix 2.13) that focus on the chemistry behind everyday reactions. Articles could concentrate on such examples as cooking/baking, bleaching hair, oxidation of paint, and fermentation.

2.   Students carry out a “Reading for Understanding” assignment and identify key points from their chosen articles through a question and answer format.

Assessment

Assess using Reading for Understanding Rubric (Appendix 2.14).

Accommodations

Enlarge print for students with poor vision. Use scribe and/or peer helpers, tape recorder, or computer as alternative to written response. Allow students to respond orally.

1.12 Summative Assessment Task:  Station-Based Activity

Students carry out a station-based assessment task that involves six different stations. Each station revisits tasks that were covered in this activity.

Teacher Facilitation

1.   Prepare worksheet for Station-Based Activity. Worksheet should include spaces to record student observations and address specific conclusions that can be made from each station (Appendix 2.15).

2.   Introduce the activity. Group students into pairs (lab partners) to complete the following investigations: lab safety/equipment identification, physical change vs. chemical change identification, lit candle chemical change observation, copper wire in silver nitrate experiment, baking soda + vinegar in a balloon experiment, Reading for Understanding assignment (baking bread).

3.   Students gather the data for this lab in pairs, but work on the conclusions separately. This method ensures proper summative assessment.

4.   Gather material for experiments described below.

Station 1:  Lab Safety/Equipment Identification

1.   Place a number of pieces of equipment out at this station and number them using masking tape. Each number corresponds to the equipment that is identified.

2.   Included at this station is a Cloze worksheet that identifies the safety equipment throughout the lab room.

Station 2:  Physical Change vs. Chemical Change Lab

1.   Students place anhydrous copper(II) sulfate in water and record their observations. Inferences are made as to whether this is a physical or chemical change.

2.   Students place a small sample of steel wool (previously cleaned with alcohol to degrease it) in a copper(II) sulfate solution and record their observations. Inferences are made with regards to this being a physical or chemical change.

3.   Students place copper(II) sulfate in a sodium hydroxide solution and record their observations. Inferences are made as to whether this is a physical or a chemical change.

4.   Students place a small magnesium sample in dilute (less than 0.01M) hydrochloric acid and record their observations. Inferences are made in regards to this being a physical or chemical change.

Station 3:  Candle Observation

Students light a small candle and make all observations with regards to the characteristics of both physical and chemical change.

Station 4:  Precipitate Experiment

Students obtain a piece of copper wire and place it in a silver nitrate solution. Observations are made with regards to this precipitate experiment.

Station 5:  Baking Soda/Vinegar in a Balloon Experiment

Students obtain baking soda and vinegar and place these substances into a balloon. Observations are made on this gas producing reaction.

Station 6:  Reading for Understanding (Baking Bread)

Provide a Reading for Understanding article on baking bread and how this is a chemical reaction. An attached Cloze worksheet will assist students in identifying the chemical changes involved in this process.

Safety Precautions

Use care in handling solutions, especially the silver nitrate, acids, and bases. Wear safety glasses and take precautions around the candle flame.

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines

The following MSDS information is provided:

Copper wire: Use microamounts when using. Dispose of in a waste disposal jar.

Silver nitrate: Danger! Strong oxidizer! Contact with other materials may cause a fire. Causes skin burns. Dispose of using a waste disposal jar.

Baking soda (sodium bicarbonate): Use microamounts when using.

Vinegar: Do no use glacial acetic acid. Use household vinegar. Vinegar may be flushed down the drain with excess water.

Assessment

Assess using a worksheet answer key for the station-based work. Assess the lab performance using the Lab Procedures Rubric (Appendix 2.3).

Note: Since this is a summative assessment, it is important that each student is graded independently.

Accommodations

Provide a peer helper to assist in carrying out lab and recording data.

Resources

See Resources for the unit.

 

Activity 2:  Acids and Bases

Time:  690 minutes

Description

Students become familiar with the properties of acids and bases and are able to identify common acids and bases by their chemical formulae and common names. The pH scale is used in conjunction with pH and litmus paper to test common substances for their acidic/basic properties. Knowledge and lab activities on this topic are extended to the neutralization process and the formation of salts by acids reacting with bases to form water and salts.

Strand(s) and Expectations

Strand(s):  Chemistry

Specific Expectations

CH1.05 – state the properties of acids and bases and identify some common acids and bases by their common names and chemical formula (e.g., sulfuric acid, hydrochloric acid, nitric acid, sodium hydroxide, calcium hydroxide...);

CH1.06 – classify some common household materials as acids and bases;

CH1.07 – explain how the pH scale is used to identify acids and bases;

CH1.08 – describe the neutralization process, the formation of salts and identify some common salts by their formula;

CH2.01A – demonstrate knowledge of safety procedures when carrying out investigations in the laboratory using materials, tools, and equipment to carry out chemical reactions (e.g., wear safety glasses, use care when heating materials, follow WHMIS guidelines and emergency procedures, use proper procedures for handling, storage and disposal of chemicals);

CH2.01C – demonstrate the skills required to investigate chemical reactions, using instruments, tools, and apparatus safely, accurately, and effectively (e.g., evaporating water in a neutralization reaction to recover the salt; determining the properties of acids and bases; simple synthesis, decomposition and oxidation reactions);

CH2.01F – communicate scientific ideas, procedures, results, and conclusions about chemical reactions using appropriate language and formats (e.g., sharing in small groups; demonstrations; structures laboratory reports).

Planning Notes

Task 2.12 requires the preparation of a research paper on suggested topics involving acids and bases. Preplan with teacher/librarian and book access to computer lab or Internet.

Equipment required for Task:

·         2.1 – Video on “Acids and Bases”, or antacid ads from magazines. Teachers are reminded to follow copyright regulations when showing videos.

·         2.2 – apple, lemon, brussel sprouts, dill pickles, milk, tonic water, vinegar

·         2.3 – dilute (less than 0.01M) acetic acid, dilute (less than 0.01M) hydrochloric acid, blue and red litmus paper, phenolphthalein indicator, tap water, magnesium ribbon, dilute (less than 0.01M) sodium hydroxide solution, dilute (less than 0.01M)

·         dilute (less than 0.01M) ammonium hydroxide solution, test tubes, slides, glass stirring rods

·         2.4 – zinc metal, dilute (less than 0.01M) hydrochloric acid

·         2.5 – molecular model kits

·         2.7 – antacid tablets, toilet bowl cleaner, lemon juice, coffee, vinegar, liquid stomach antacid, drain cleaner, window cleaner, bleach, tea, and the following indicators (methyl orange, phenolphthalein, litmus, bromothymol blue), pH paper (Universal indicator)

·         2.8 – universal indicator paper, orange, grapefruit, milk, vinegar, aspirin, grape juice (white), calcium hydroxide solution, ammonium hydroxide solution, potassium hydroxide solution, water, ground almond solution, glass cleaner

·         2.9 – sodium hydroxide solution, tap water, hydrochloric acid solution, silver nitrate solution, indicator, pH paper (Universal indicator), evaporating dish, graduated cylinder, medicine dropper, glass stirring rod

·         2.10 – neutralized solution from Task 2.9, retort stand, noculating loop, wire gauze, Bunsen burner, evaporating dish, glass slide, microscope, medicine dropper, silver nitrate solution

Prior Learning Required

The understanding of and ability to practise safety in the laboratory developed in the previous activity is revisited.

Teaching/Learning Strategies

2.1 Learning Task:  Introduction to Acids and Bases

Students view a video on acids/bases (Bill Nye) or look at an ad on acids and bases (Antacids) and participate in a teacher led discussion on acids and bases, found in both home and workplace products, and their use.

Teacher Facilitation

1.   Utilize a video resource on acids/bases to introduce this activity. Teachers are reminded to follow all copyright regulations when showing videos. Alternately, look at advertisements in magazines on antacids. [Note: The key ideas for this unit are: acids and bases have numerous uses in everyday life; compounds classified as acids have characteristic properties; compounds classified as bases have characteristic properties, some of which are different from those of acids; chemical and natural indicators undergo a colour change in the presence of acids and bases; neutralizations are important acid-base reactions; acids and bases can be corrosive and must be handled with extreme caution. Many acids and bases are not corrosive. For example, cola drinks have acidic properties and they are consumed. Antacids, both solid and liquid, are consumed to aid in treating heartburn symptoms; and acids and bases can be recognized by their names.]

2.   Carry out a teacher-led discussion that elaborates on the key ideas of this unit.

3.   Have students record the key ideas in a short note.

Assessment

None.

Accommodations

Use scribe, and/or peer helper, tape recorder, or computer as an alternative to written response.

2.2 Learning/Diagnostic Task:  Sour vs. Bitter

Students classify different foods according to taste in chart form. If students have food allergies, substitutions can be made.

Teacher Facilitation

1.   Obtain a variety of foods for use in this lab including apple, milk, lemon, tonic water, brussel sprouts, vinegar, and dill pickles.

2.   Remind the students that tasting substances is rarely carried out in a lab.

3.   Provide a lab worksheet for recording data. See Appendix 2.16.

4.   The worksheet has a question involving the types of acids associated with foods. The following information may prove to be useful:

Substance

Name of Acid

orange, lemon, grapefruit

citric

sour milk, sour cream

lactic

vinegar

acetic

aspirin

acetylsalicylic

apple, grape

malic

Safety Precautions

Teacher should check with all students regarding food allergies. Preparation of the food for tasting should involve careful procedures. Teacher prepares food and stores it in a sealed container or covers it with plastic wrap. All students should wash their hands at the beginning of the lab to maintain aseptic conditions. Liquids should be poured from a sealed container into paper cups that can be disposed of after taste testing has been carried out. Students should be instructed not to share food that has been tasted by themselves with others. Food is disposed after being tasted by the student.

Assessment

Assess using a worksheet answer key.

Accommodations

Data can be recorded with peer assistance. Enlarged print can be utilized for sight-impaired students.

2.3 Learning/Diagnostic Task:  Properties of Acids and Bases

Students use litmus paper to identify common acids and bases. This data is recorded in chart form. The effect of acids and bases on magnesium ribbon and phenolphthalein indicator will also be recorded. A simple touch test will also be performed with acids and bases.

Teacher Facilitation

1.   Lead discussion on how using taste for identifying acids and bases is not only impractical, but extremely dangerous.

2.   Introduce the concept of using an indicator in the form of litmus paper for identifying acids and bases. Litmus is a dye that is extracted from a type of plant called lichen. Litmus is blue in its natural state and turns red if an acid is added to it. Red litmus turns blue if a base is added to it. Tea can also be used as an indicator; it forms a red solution in an acid and dark brown solution in a base.

3.   Students observe and record the effect acids and bases have on blue and red litmus paper, phenolphthalein indicator, magnesium ribbon, and on human skin (simple touch test) in chart form on worksheet provided. (See Appendix 2.17.)

4.   The touch test will only be carried out on the dilute vinegar and the dilute (less than 0.01M) sodium hydroxide solution.

5.   Note: Teacher may substitute indicator paper with a pH meter if one is available. The use of a pH meter could also serve as an extension to this task.

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

The following MSDS information is provided:

Acetic acid (vinegar): Do not use glacial acetic acid for this experiment. Use household vinegar. Flush down drain with excess water.

Ammonium hydroxide: Use microamounts when using. Danger! Corrosive. Toxic. Dispose of in waste disposal jar.

Hydrochloric acid: Add acid to water and not water to acid when carrying out a dilution. Use microamounts when using. Corrosive! Absorb spills using an absorbent, non-combustible material such as earth, sand, or vermiculite. Dispose of using a waste disposal jar.

Magnesium: Use microamounts when using. Dispose of using a waste disposal jar.

Phenolphthalein: Use microamounts when using. Dispose of using a waste disposal jar.

Sodium hydroxide: Danger! Corrosive. Causes severe eye and skin burns. Contact with moisture or water may generate sufficient heat to ignite nearby combustible materials. Ensure that the dilution of sodium hydroxide in this lab is 0.001 M. Wash thoroughly with water after any contact is made. Dispose in a waste disposal jar.

Assessment

Assess using worksheet answer key.

Accommodation

Pair students to complete experiment. Have a scribe aid in completion of worksheet.

2.4 Learning Task:  Acid/Base Discussion and Note Taking

Students participate in a teacher-led discussion that elaborates on the characteristics of acids and bases. The labs carried out in Task 2.2 (Sour vs. Bitter) and 2.3 (Properties of Acids and Bases) provide the knowledge/fact base for this note.

Teacher Facilitation

1.   Carry out a demonstration involving zinc metal and hydrochloric acid to introduce this activity. The production of hydrogen gas can be demonstrated by carrying out a burning splint test. This demonstration begins the discussion of acids and bases.

2.   Remind the students of the two labs that were carried out in prior classes (Sour vs. Bitter and Properties of Acids and Bases)

3.   Note: Acids are a group of substances that have the following properties: acids conduct electricity when in solution, acids react with active metals to liberate hydrogen gas, acids change the colour of litmus and other dyes (turns blue litmus red), acids react with bases to form new substances, acids react with carbonates and bicarbonates, and acids have a sour taste.

4.   Note: Bases are a group of substances that have the following properties: bases conduct electricity when in solution, bases change the colour of litmus and other dyes to colours different from those of acid solutions (turns red litmus blue), bases react with an acid to produce new substances, bases are slippery to the touch, bases do not react with carbonates and bicarbonates, and bases have a bitter taste.

Assessment

None.

Accommodations

Provide a peer helper to assist students with writing when necessary.

2.5 Learning Task:  What is a Chemical Formula?

Students are given the definition of a chemical formula (series of symbols of elements linked together to form the symbolic representation of a compound; it shows the relative number of atoms of each element in the compound) and apply this definition to a worksheet involving common acids and bases. The elements present and their relative number are identified in chart form with the use of a periodic table.

Teacher Facilitation

1.   Prepare a note that covers the basics behind a chemical formula. A chemical formula represents a series of elements that are linked together to form a compound.

2.   Utilize a molecular model kit to demonstrate common acids and bases that have been used in the lab: HCl (Hydrochloric acid), H2SO4 (Sulfuric Acid), NaOH (Sodium Hydroxide).

3.   Indicate to the students how the Periodic Table is used to identify the element and how the subscript number that follows the symbol of the element in a formula identifies the total number of atoms of each element in the acid or base compound.

4.   Provide a chart as follows: (See also Appendix 2.18)

Formula

Elements Present

Number of Each Element

Acid/Base

Name

HC1

Hydrogen Chlorine

1

1

Acid

Hydrochloric Acid

HNO3

 

 

 

Nitric Acid

NaOH

 

 

 

 

Assessment

Worksheet answer key

Accommodations

Provide a peer helper to assist students with writing when necessary.

2.6 Learning Task:  The pH Scale

Students read a pH scale and identify on this scale where common acids and bases are found. The strength of acids and bases is measured by using the pH scale.

Teacher Facilitation

1.   Lead a discussion on scales and how they are used in all walks of life. Describe a scale as the rule or system upon which a series is laid down. Provide common examples of scales that are used everyday, e.g., measuring temperature with a thermometer, measuring speed with a speedometer, measuring volume with a graduated cylinder, mass measurement with a balance, and length measurements with a ruler.

2.   Introduce the pH scale as a scale that is used to measure the strength of acids and bases. (Note for teacher reference: the pH scale is logarithmic; for every decrease of 1 in the pH scale, the acid strength increases by 10X; therefore, an acid with pH of 2 is 10X more acidic that an acid with pH 3).

3.   Provide students with universal pH paper and the colour coded scale so as to show that the pH scale is a numerical scale that runs from 0 to 14.

4.   Provide students with a pH table that indicates where some common substances exist. See Appendix 2.19.

5.   Students use Appendix 2.19 to indicate on a pH scale where some common substances exist. Students interpret the table of pH values and use a ruler to graphically indicate where these substances are found on the pH scale.

6.   As enrichment, students could test the substances used in step 5 using a pH meter and compare the pH values obtained using the meter and with those using the universal pH paper.

Assessment

Create an answer sheet for Appendix 2.19.

Accommodations

Provide a scribe for recording answers.

2.7 Learning Task:  Testing for Acids and Bases in Ten Consumer Products

Students test ten common household products for their acidic or basic characteristics and record their observations in chart form. Acidic and basic properties are determined through the use of chemical indicators (e.g., methyl orange, phenolphthalein, litmus, and bromothymol blue).

Teacher Facilitation

1.   Lead a discussion on indicators and how they are used to determine the characteristics of a substance. Acidic and basic substances can be identified using chemical indicators. The following chart is provided:

Indicator

Colour In Acid

Colour In Base

Methyl orange

Red

Yellow

Litmus

Red

Blue

Bromothymol blue

Yellow

Blue

Phenolphthalein

Colourless

Pink

 

2.   Introduce the fact that many common household products contain either acids or bases. Each product has its own chemical properties that make it useful for different chores. When you have a tough cut of beef, you can make it tender by marinating it. The marinade, whether it is lemon juice, wine, or vinegar reacts with the tough connective tissue to soften it. These are liquids that have acidic properties. Soaps, which are used to clean dishes, clothes, and hands, contains a base that reacts with the oils and dirt to remove them.

3.   Introduce Appendix 2.20. Students test for acids and bases in ten consumer products using the indicators introduced at the beginning of this discussion.

4.   Review lab routines and safety procedures with the students. The Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3) could be introduced to the students as the assessment tools that will be used to monitor lab safety.

5.   Demonstrate how to use pH paper (Universal) to determine if a solution is acidic, basic, or neutral.

6.   Introduce the concept of acidic, basic and neutral solutions by discussing some characteristics such as taste, e.g., acids such as vinegar, and lemon juice taste sour; bases, such as liquid antacids, solid antacids, and almond oil, taste bitter; colour of indicator (Universal) reflects the pH level; and the effects on living organisms (e.g., both strong acids and strong bases are corrosive).

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

Caution: Strong acids and bases are corrosive.

Use microamounts of the consumer products tested. Dispose of using a waste disposal jar.

The following MSDS information is provided:

Bromothymol blue: Use microamounts. Regarded as an essentially non-hazardous chemical that may stain skin. Dispose of by flushing down the drain with excess water.

Phenolphthalein: Use microamounts. Dispose of using a waste disposal jar.

Methyl orange: Use microamounts. Dispose of using a waste disposal jar.

Litmus: Use microamounts. Dispose of using a waste disposal jar.

Assessment

Assess student work using a teacher created answer key. Assess lab work using Lab Procedures Rubric (Appendix 2.3) and Lab Safety Checklist (Appendix 2.2).

Accommodations

Teachers may choose to have students complete only part of this activity. A scribe may be assigned for students who might have difficulty completing the lab and accompanying worksheet.

2.8 Assessment Task:  pH Determination of Acids and Bases

Students determine the pH of 12 household products using universal indicator paper. This information is recorded in chart form and the substances are determined to be acidic, neutral, or basic.

Teacher Facilitation

Prior to lab:

1.   Prepare the following samples for the pH lab including: orange, grapefruit, milk, vinegar, aspirin, grape juice (white), calcium hydroxide solution (less than 0.01M), ammonium hydroxide solution (less than 0.01M), potassium hydroxide solution (less than 0.01M), water, ground almond solution, and glass cleaner.

2.   Prepare a worksheet to guide students in performing the lab and entering their data. (See Appendix 2.21).

3.   Obtain a supply of universal indicator paper that is colour coded for recording the pH level of the substances used in this lab activity.

During lab:

4.   Students follow the Lab Procedures Rubric (Appendix 2.3) and the Lab Safety Checklist (2.2) during this lab activity. Introduce these tools at the beginning of the lab activity.

5.   Demonstrate how to use the universal indicator paper and how to determine the pH value from the colour code provided.

6.   Record the information from this lab in the worksheet provided (Appendix 2.21).

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

Use microamounts of household and commercial products when testing for pH.

The following MSDS information is provided:

Ammonia water: Use microamounts. Dispose of using a waste disposal jar.

Calcium hydroxide: Use microamounts. Caustic irritant to eyes, skin, and respiratory tract. Dispose of using a waste disposal jar.

Potassium hydroxide: Use microamounts. Caustic irritant to eyes, skin, and respiratory tract. Dispose of using a waste disposal jar.

Assessment

Assess lab work using Lab Procedures Rubric (Appendix 2.3) and Lab Safety Checklist (Appendix 2.2). Assess student work using teacher-created answer key.

Accommodations

Provide a scribe to assist in recording data. Lab partners can be arranged to assist in aiding students throughout this lab activity.

2.9 Learning/Assessment Task:  Neutralizing Acids

Students carry out and observe a neutralization reaction. A base will be neutralized by the addition of an acid and the amount of acid that is required to neutralize the base is recorded. The neutralization reaction is observed using an indicator.

Teacher Facilitation

1.   Introduce the concept of neutralization by referring to the pH scale. The middle point of the pH scale (7.0) represents the point at which the substance is neither acidic or basic. Distilled water can be used to demonstrate neutrality with the use of a universal indicator strip, and/or a liquid indicator that has been used in past experiments (methyl orange, litmus, phenolphthalein, or bromothymol blue). (Note: Distilled water is mildly acidic because it contains dissolved CO2; let it sit overnight before using the distilled water. Depending on the geographical location, tap water may be slightly acidic or basic).

2.   Provide the students with the lab worksheet (Appendix 2.22). Go over the lab worksheet and the requirements for this lab activity.

3.   Students should be informed that they will be observing and recording a neutralization reaction in the lab.

4.   Students use universal indicator paper, dilute (less than 0.01M) hydrochloric acid, and dilute (less than 0.01M) sodium hydroxide solution in this lab. The pH of the original solutions is recorded, and the pH of the final solution after it has been neutralized is recorded as well. Phenolphthalein is used as the indicator for this experiment.

5.   Save the material in the evaporating dish as it will be used for the next Task (2.10: What is a Salt?).

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

Use microamounts of materials if possible.

The following MSDS information is provided:

Hydrochloric acid (dilute - less than 0.01M): Add acid to water and not water to acid when carrying out a dilution. Absorb spill using an absorbent, non-combustible material such as earth, sand, or vermiculite.

Phenolphthalein: Use microamounts. Dispose of using a waste disposal jar.

Sodium hydroxide: Danger! Corrosive. Causes severe eye and skin burns. Contact with moisture or water may generate sufficient heat to ignite nearby combustible materials. Use microamounts. Dispose of using a waste disposal jar.

Assessment

Use Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3) to assess lab work. Assess student work using teacher-created answer key.

Accommodations

Group students so that they can assist one another.

2.10 Learning/Diagnostic Task:  What is a Salt?

Student utilizes the neutralized material (hydrochloric acid and sodium hydroxide) from Task 2.9 to observe and record the products of a neutralization reaction.

Teacher Facilitation

1.   Lead a brief discussion on the results of the last lab activity (Task 2.9). Discuss that when an acid is mixed with a base, the new solution is neither an acid nor a base. It is neutral. The process is called neutralization. The pH of a neutralized solution is 7.0.

2.   Provide the chemical formula for the substances involved in the reaction from Task 2.9.

Substance

Chemical Formula

Elements Present

Sodium hydroxide

NaOH

Na, O, H

Hydrochloric acid

HCl

H, Cl

3.   Have students hypothesize the possible products of this reaction. Record the results on the board for reference after the lab activity is carried out.

4.   Provide the students with a lab activity sheet involving salts (Appendix 2.23). Go over the steps of this lab activity. The focus of this lab activity is to observe and record the products from a neutralization reaction.

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after handling.

Disposal: Refer to federal, provincial, and local guidelines.

The following MSDS information is provided:

Hydrochloric acid: Caution! Caustic. Use microamounts. Dispose of using a waste disposal jar.

Sodium hydroxide: Danger! Corrosive. Causes severe eye and skin burns. Contact with moisture or water may generate sufficient heat to ignite nearby combustible materials. Dispose of using a waste disposal jar.

Assessment

Use Lab Safety Checklist (Appendix 2.2) and Lab Procedures Rubric (Appendix 2.3) to assess lab work. Assess student work using teacher-created answer key.

Accommodations

Pair students of appropriate ability level together to assist in recording of observations and reading comprehension.

2.11 Assessment Task:  Acid Rain

Students complete a Reading for Understanding assignment on Acid Rain, its sources, its effects, and how it can be stopped.

Teacher Facilitation

1.   Students participate in a teacher-led discussion on acid rain, what it is, where it originates from, and how this environmental problem can be addressed. Points brought up throughout the discussion can be placed on the board.

2.   A Reading for Understanding assignment on Acid Rain (Appendix 2.24) is handed out and students complete the assignment questions and the accompanying Cloze worksheet assignment.

Assessment

Assess using Reading for Understanding Rubric (Appendix 2.14).

Accommodations

Provide a peer helper/scribe to assist in reading and recording answers.

2.12 Assessment Task:  Acid Rain Research Paper

Note: Teachers may choose to use this task as a summative assessment in which case each student is graded individually. Students participate in a teacher-led discussion on acid rain, its effects, and how it can be reduced. Based on discussion, class generates a list of topics that are connected to acid rain and the environment. Students complete a research paper using the Research Paper Template. (See Appendix 2.31).

Teacher Facilitation

1.   The focus of this activity is to emphasize the danger of acid rain to the environment.

2.   Lead students through a discussion on the effects of acid rain and the resulting harmful effects on the world in which we live. Use pictures and/or video clips to aid in the discussion if desired. Teachers are reminded to follow copyright regulations when showing videos

3.   Aid students in organizing the list and recording it in their notebooks.

4.   Instruct students to choose one of these factors and complete a research paper. Students should use the Research Paper Template (Appendix 2.31) focussing on the problem and any solutions.

5.   Some possible topics for this research paper assignment are as follows: where acid rain comes from; effect of acid rain on aquatic organisms; effect of acid rain on plant life; effect of acid rain on terrestrial organisms; treatment of acidified lakes; treatment of acidified soil; effect of acid rain on marble buildings and tombstones; production of acid rain, regional study of acid rain fallout; why limestone lakes of Eastern Ontario are not affected by acid rain; and the effect of acid rain on human health.

6.   Provide students with research material and access to the library and the Internet.

Assessment

Assess using the Research Paper Rubric (Appendix 2.33).

Accommodations

Assign a peer helper to assist with research and reading. Use scribe, tape recorder, or computers as an alternative to written responses.

Resources

See resources for the unit, particularly those dealing with acid rain.

 

Activity 3:  Chemistry in Our Everyday Lives

Time:  420 minutes

Description

Chemical reactions in everyday life are examined with the specific focus on the use of common chemical reactions in various careers. Students complete a culminating activity that examines the impact of chemistry (more specifically chemical reactions) on the environment.

Strand(s) and Expectations

Strand(s):  Chemistry

Overall Expectations

CHV.03 – demonstrate an understanding of the differences between chemical and physical changes.

Specific Expectations

CH2.01B – formulate scientific questions about chemical reactions (e.g., how does changing the temperature affect the rate of the reaction?);

CH2.01D – select information from various sources to answer the questions formulated;

CH2.01E – organize, record, and analyse the information gathered during investigations of chemical reactions (e.g., charts, tables, graphs);

CH3.01 – identify the uses of acids, bases and salts in the workplace or home environment by researching labels on common household products;

CH3.02 – describe activities in the workplace and household where knowledge of chemicals can prevent hazardous situations;

CH3.03 – identify careers or hobbies where a knowledge of chemical reactions is important.

Planning Notes

Task 3.5 – arrange a guest speaker to discuss a career related to chemistry

Task 3.6, 3.7, and 3.8 – pre-plan visit with teacher/librarian or book computer lab time for research using the Internet

Equipment required for Task:

·         3.1 – lab equipment to be determined by teacher

·         3.2 – samples of comic strips, material for comic strip (pencil crayons, paper)

·         3.3 – enlarged labels of three household products

·         3.4 – ten common household products, representative of acids, bases, and salts

·         3.6 – research material (newspapers, videos, CD-ROMs)

·         3.7 – poster making materials (crayons, markers, bristle board)

·         3.8 – video on current environmental chemistry issue

Teachers are reminded to follow copyright regulations

Prior Learning Required

Several expectations from Grade 9 are revisited. Knowledge of chemical reactions and physical/chemical change are developed further. Safety and WHMIS are examined with focus on their applications in everyday life.

Teaching/Learning Strategies

3.1 Learning Task:  Chemistry in Everyday Life

Students participate in small lab activities involving chemical reactions in everyday life. The lab activity is used as a basis for a class discussion and concept mapping activity.

Teacher Facilitation

1.   Gather materials to carry out a variety of lab activities including bleaching cloth, tye-dyeing T-shirts, fermentation of yeast, or cooking food. (See Appendix 2.25). Materials gathered may also include pictures of various chemical reactions including a running car, a person smoking a cigarette, a fire burning, etc.

2.   Lead a discussion focussing on how chemistry applies to everyday life.

3.   Complete concept mapping activity (Appendix 2.9) which focusses on everyday chemical reactions. Possible descriptors include: chemical reactions, cleaning, combustion, cooking, baking, etc. Connectors include: at work, at home, such as, including.

Safety Precautions

Students are to wear goggles and protective clothing; hands should be washed thoroughly after the lab. Waste should be disposed in a waste disposal jar.

Assessment

None.

Accommodations

Pair students for lab work. Some experiments can be done as teacher demonstrations.

3.2 Assessment Task:  Chemical Reactions in Life

Students create a comic strip showing four chemical reactions in their everyday lives.

Teacher Facilitation

1.   Review the idea of chemical reactions in everyday life.

2.   Gather examples of various comic strips for students to examine. Direct students to locate examples of chemical reactions in comic strips. Students circle each example and write a sentence describing the chemical reaction.

3.   Post comic strips around the room for future reference.

4.   Create a worksheet to lead students through the activity of creating a comic strip showing four chemical reactions in everyday life.

5.   Discuss Comic Strip Checklist (Appendix 2.26) so students are aware of the evaluation to be used.

Assessment

Assess using Comic Strip Checklist (Appendix 2.26).

Accommodations

Allow students to present information in a form other than a comic strip (e.g., poster, video, rap song, slide presentation, or drama).

3.3 Learning Task:  Classification of Household Products

Students identify ingredients on common household products as acids, bases, or salts. Students summarize findings on a worksheet.

Teacher Facilitation

1.   Enlarge labels found on three common household products.

2.   Lead students though activity in which students identify product; the active ingredient in product that is an acid, base, or salt; and the use of the product. See Appendix 2.27 for sample worksheet.

3.   Examples of products include a cola which contains phosphoric acid and carbonic acids. In soya sauce and bouillon cubes there is sodium chloride (salt); drain cleaner contains sodium hydroxide (base); yogurt contains lactic acid.

Assessment

Assess using teacher-created answer key.

Accommodations

Assign a peer helper to assist with writing.

3.4 Assessment Task:  Acid, Base, or Salt?

Students complete worksheet identifying ten common household products as acids, bases, or salts.

Teacher Facilitation

1.   Gather ten household products containing acids, bases or salts.

2.   Prepare worksheet to guide students through the activity. (See Appendix 2.28)

3.   Examples of products include: vinegar which contains acetic acid, citrus fruits (acidic), most cleaning products (e.g., laundry detergent, floor cleaner) contain bases and salts.

Assessment

Assess using teacher-created answer key.

Accommodations

Assign a peer helper to assist with reading and writing.

3.5 Learning Task:  Guest Speaker

Student awareness of chemical reactions in everyday life is broadened with a visit from a guest speaker. Students learn about chemical reactions that are used everyday on the job.

Teacher Facilitation

1.   Arrange a guest speaker to talk to the class about his/her job. Discussion should also cover the chemicals used, with emphasis on the safety precautions used on the job. Possibilities include the school custodian, a cosmetologist, a technician from a paint manufacturer, and a salesperson from a cleaning products supplier.

Assessment

None.

Accommodations

Use of video or teacher-developed Reading for Understanding article if guest speaker is unavailable.

3.6 Assessment Task:  Careers in Chemistry

Students research careers in which knowledge of chemistry and chemical reactions is essential. Information is recorded on a worksheet for use in poster making activity.

Teacher Facilitation

1.   Lead a brainstorming activity on careers which use chemical reactions. Instruct students to choose one career from list generated.

2.   Create a worksheet to guide students through the activity. Focus student research on careers and the chemistry involved in the job. (See Appendix 2.29) Worksheet should also have a section created in which students record information about safety precautions used in the career being researched. This information will be used in the next task.

3.   Provide students with information on careers listed. Information could come from newspapers, the Internet, library searches, CD-ROMs.

Assessment

Assess using teacher-created checklist.

Accommodations

Provide peer helpers to assist with research and writing.

3.7 Assessment Task:  Safety Poster

Using research from Task 3.6, students create a safety poster. The poster shows the chosen career with emphasis on the safety precautions that are taken on that job.

Teacher Facilitation

1.   Gather poster-making materials.

2.   Introduce students to Poster and Presentation Rubric (Appendix 2.30) so they become familiar with criteria of evaluation and are able to judge the quality of the poster they are creating.

3.   Assist students in organization of material and time management.

Assessment

Assess using poster portion of Poster and Presentation Rubric (Appendix 2.30).

Accommodations

Allow students to present information in a form other than a poster (e.g., a video, slide presentation, drama, comic strip, or any other suitable form of communication). Teachers are reminded to follow copyright regulations when showing videos.

3.8 Learning Task:  Introduction to Environmental Chemistry

Students view video or short TV segment on chemistry in the environment and complete a question sheet.

Teacher Facilitation

1.   Select and show a video that focuses on environmental chemistry (e.g., cigarette smoking, acid rain, global warming, the banning of pesticides/herbicides in communities, the safe disposal of oil, the clean up of oil spills, the effects of cigarettes smoking on the body, the disposal of chemicals in the home, the effect of using solvents, such as turpentine, when cleaning skin). Teachers are reminded to follow copyright regulations when showing videos.

2.   Prepare a worksheet with focus questions on video. Sample questions may include: “What is the problem?, “What are the causes of the problem?”, “What effect does the problem have on the environment?”.

3.   Lead a discussion on the environment and the effects of chemical reactions.

4.   Alternate assignment: Students select a news article with the same focus. Students then answer the five W and H questions (who, what, where, when, why and how).

Assessment

Assess using teacher-created answer key.

Accommodations

Use of closed-captioning for deaf and hard of hearing students. Assign a peer helper to assist in the completion of the worksheet.

3.9 Learning/Assessment Task:  A Closer Look at the Environment

Students complete an SLL entry on a current environmental issue.

Teacher Facilitation

1.   Prepare an SLL entry sheet with vocabulary (e.g., chemistry, reaction, pollution, pesticide) and focus task (e.g., “I think pesticides should or should not be banned because…”). Include a connections statement (e.g., “One thing I would like to learn about how chemistry affects the environment is…).

Assessment

Assess using SLL Rubric (Appendix OV-3).

Accommodations

Provide peer helper to assist with writing.

3.10 Assessment Task:  Chemistry and the Environment

Note: Teachers may choose to use this task as a summative assessment in which each student would be graded individually. Using connections question generated from SLL entry in Task 3.9, students complete a research paper examining the influence chemistry has on the environment. Students are to formulate a question and use it as the basis for their research. Students complete a Research Paper Template (Appendix 2.31) on the environmental issue.

Teacher Facilitation

1.   Go through model Research Paper Template Sample with students explaining how it follows the template (Appendix 2.32).

2.   Students using connections question from SLL entry in previous task as basis for research paper.

3.   Prepare materials and book access to Library/Resource Centre and Internet.

4.   Introduce students to assessment tool and format of research paper.

Assessment

Assess using Research Paper Rubric (Appendix 2.33).

Accommodations

Assign a peer helper to assist with reading and research. Use scribe, tape recorder, or computer as an alternative to written responses.

Resources

Environment Canada’s web site with a primer on ozone depletion
http://www.ec.gc.ca/ozone/primer/index.htm

 

 


Appendix 2.1

Introduction to Lab Safety

Reference for Unit 2, Task 1.1.

 

Parts and Functions

Complete the following chart by matching the correct name with the use of the item. Sketch a picture to represent the item. Sample answers are given for 3 and 11.

 

Item

Name (from list)

Description or Sketch

Uses or Function (from list)

1

 

 

 

2

 

 

 

3

fire Extinguisher

red cylinder (sketch of fire extinguisher with cone nozzle and handle)

E.Puts out fires

~

10

 

 

 

11

test tube

(sketch of test tube)

J. Glass tube, rounded on bottom, that holds about 30 mL of liquid

12

 

 

 

 

 

 

Item Names

 

Use or Function

first-aid kit

A.

Broken glassware goes into it

Safety goggles

B.

Measures temperature in Celsius degrees

fire extinguisher

C.

Produces a gas flame for heating

250 mL beaker

D.

Used to measure up to 100 mL of liquid

hot plate

E.

Puts out fires

microscope

F.

Protects eyes when working in a lab

100 mL graduated cylinder

G.

Electrical devices used to heat materials

broken glass container

H.

Magnifies biological specimens so you can see them

thermometer

I.

Used to wash splashed material from the eye

eye wash station

test tube

J.

Glass tube, rounded on bottom that holds about 30 mL

of liquid

Erlenmeyer flask

waste blanket

K.

Made of glass, liquids are mixed in it, holds about 200

mL

fire blanket

L.

Flask with conical shape

 


Appendix 2.2

Lab Safety Checklist

Reference for Unit 2, Task 1.2, 1.5, 1.8, 2.7, 2.8, 2.9. 2.10

 

Date:                                                                                                    Name:

 

Check if the item is done correctly.

 

Able to explain use of - eyewash station

q

- fire extinguisher

q

- fire blanket

q

 

 

Wears goggles throughout experiment

q

 

 

Has long hair tied back/no loose clothing

q

 

 

Disposes of broken glass, biology specimens or chemical waste in proper location

q

 

 

Operates equipment safely

q

 

 

Follows special instructions

q

 

 

Takes correct amount of reagent/solution

q

 

 

Does not return reagent nor contaminate source

q

 

 

Informs teacher of accident/injury

q

 

 

Behaves safely

q

 

 

Knows location of fire exit

q

 

 

Checks all electrical circuits, frayed cords with teacher

q

 

 

Identifies potential hazards in labs

q

 

 


Appendix 2.3

Lab Procedures Checklist

Reference for Unit 2, Task 1.2, 1.5, 1.8, 2.7, 2.8, 2.9, 2.10

 

These criteria measure good performance in the laboratory

 

Criteria

Level 1

Level 2

Level 3

Level 4

Follows procedures

- participates in lab with supervision

 

 

- written instructions need oral interpretation

- participates in lab with some supervision

 

- all oral instructions followed/some written instructions followed

- participates in lab with minimal or no supervision

 

- can follow written instructions

- actively assists others in completing lab

 

- able to read written instructions and assists others in interpreting them

Application of technical skills and procedures

- applies technical skills and procedures with limited competence

- applies technical skills and procedures with moderate competence

- applies technical skills and procedures with considerable competence

- applies technical skills and procedures with a high degree of competence

Use of tools, equipment, and materials

- uses tools, equipment and materials correctly with supervision

- uses tools, equipment and materials correctly with some supervision

- uses tools, equipment and materials correctly

- demonstrates and promotes the correct use of tools, equipment and materials

Concentration

- wanders away from lab area and disturbs others

 

 

 

 

 

 

- voice often sufficiently loud to disturb others

- mostly works conscientiously at own station, travel to pick up materials is not always direct

 

 

 

- voice is usually sufficiently quiet to not disturb others

- works on task, travel is purposeful and only to pick up equipment or ask the teachers questions

 

 

 

- use of voice is usually appropriate

- always on task, assists others to stay on task, recognizes when teacher needs to direct whole class, travel is organized and non-disturbing

 

- questions deal with lab and voice is quiet.

Cleanup

- needs reminders to cleanup, sometimes misplaces equipment

- usually cleans up sink, equipment, and lab bench

- always cleans up and returns equipment, discards material in proper place, cleans sink and lab bench

- thorough cleanup and monitors others, assist in collecting and distribution of materials

Safety

- uses tools, equipment, and materials safely only with supervision and prompting

- uses tools, equipment, and materials safely with some supervision and occasional prompting

- always uses tools, equipment, and materials safely

- demonstrates, promotes, and monitors the safe use of tools, equipment, and materials at all times

Disposal of excess/used substances

- needs prompting to carry out disposal in a safe manner

 

- needs to be directed to correct location, and to follow disposal instructions

- seldom needs prompting

 

 

 

- usually done in a safe manner, to correct location, to where instructed

- no monitoring or prompting necessary

 

 

- always done in a safe manner, to correct container, to where instructed

- assists in monitoring others

 

 

 

- always in a safe manner, to proper location with obvious thought on why, where instructed

(Adapted from The Ontario Curriculum, Science, Grades 9 and 10, (1999) page 46 – 47.)

 

* These categories are for diagnostic purposes only. They may be used to provide students with feedback during lab activities.

 


Appendix 2.4

Introduction to Lab Procedures

Reference for Unit 2, Task 1.2

 

Name:

Date:

Fizzy Pop Lab

Introduction: The purpose of this lab activity is to introduce the class to proper lab procedures, safe handling of glassware and chemicals, and the proper way of recording observations. This experiment will also answer the question, “What makes the ‘fizz’ sound in a soft drink?”.

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after completing lab.

Disposal: Use the waste disposal jar for the mothballs.

Aim: To determine what makes the ‘fizz’ sound in a soft drink.

Apparatus

400 mL beakers (2)

2 mothballs

water

diluted vinegar (300 mL water plus 50 mL vinegar)

10 mL baking soda solution (10 g baking soda in 200 mL water)

safety glasses

Method

1.   Pour 350 mL of water into a 400 mL beaker.

2.   Drop 1 mothball into the water. Record the observations in the chart provided.

3.   Prepare the diluted vinegar in the second 400 mL beaker. Add a mothball to that beaker. Record the observations in the chart provided.

4.   Add 5 mL of baking soda solution to each container. Record your observations for each beaker. What do you observe for each liquid?

5.   Describe the motion of the mothball in the fizzy liquid in chart form.

6.   Carefully observe the surface of the mothballs. What forms on the surface of the mothballs?

7.   What happens to the mothball once it rises to the surface of the beaker? Where do the bubbles go?

8.   Clean up your work area.

 


Appendix 2.4  (Continued)

 

Observations

 

Lab Step

Observations

Mothball in water

 

Mothball in diluted vinegar

 

Mothball in water/baking soda solution

 

Mothball in diluted vinegar/baking soda solution

 

Motion of mothball

 

Surface of mothball

 

 

Conclusions

Instructions: Answer the following questions in sentence form. Refer to your observations.

 

1.   What is produced by adding baking soda to vinegar?

 

 

 

2.   What causes the fizz in a liquid?

 

 

 

3.   What causes the mothball to rise in one of the beakers and not in the other?

 

 

 

4.   What happens when a mothball reaches the surface?

 

 

 

5.   Why does the mothball sink after reaching the surface of the fizzy liquid?

 

 

 

6.   Does anything unusual happen to the plain water, a non-fizzy liquid?

 

 

 

7.   What is unusual about the behaviour of mothballs in a fizzy liquid? What causes this behaviour?

 

 

 

8.   Why were safety glasses worn in this experiment?


Appendix 2.5

Physical vs. Chemical Change Concept Attainment

Reference for Unit 2, Task 1.3

Physical vs. Chemical Change Assignment

 

Name:

Date:

 

Instructions: Knowing the difference between a physical and a chemical change is crucial when working with chemicals in the home and in the workplace. Use the following checklist for Physical and Chemical Change characteristics to categorize the pictures provided as either Physical or Chemical. Record, in the checklist outlined on this sheet, the category that the picture belongs to and the reason why it has been placed in the physical or the chemical change column.

 

Physical Change Characteristics

·         A physical change alters only the form of a substance.

·         Physical changes are reversible.

·         The chemical compositions of substances are not changed in physical changes.

 

Chemical Change Characteristics

·         A chemical change transforms a substance into a new product.

·         Chemical changes are not reversible. (Teacher Note: in a closed system, chemical reactions are often reversible; in many lab conditions where the system is open or when a gas or precipitate are formed, chemical reactions are not readily reversible).

·         Any, or all of the following, are characteristics of chemical change: production of heat, light, gas, precipitate; colour change.

 

Picture Number

Physical Change

Chemical Change

Reason Why It Is a Physical or a Chemical Change that is Represented in Picture

1

 

 

 

2

 

 

 

3

 

 

 

4

 

 

 

5

 

 

 

 

Conclusions

1.   What pictures demonstrated physical changes occurring?

 

 

2.   What pictures demonstrated chemical changes occurring?

 

 

3.   List two examples of chemical changes and two examples of physical changes that are not in this assignment.


Appendix 2.6

Physical Change vs. Chemical Change Checklist

Reference for Unit 2, Task 1.4

 

Physical vs. Chemical Change Checklist

 

Name:

 

Background: In a physical change no new substances are formed. An example of a physical change would be water turning into ice. The change is reversible. In a chemical change a new substance is formed. When wood is burned the following products are created: heat, light, gas, and carbon ash. Chemical changes are characterized by the following things: heat absorbed/released, light produced, gas produced, colour change, and precipitate forming.

 

Assignment:  Indicate in the following chart whether the change indicated is either a physical or a chemical change. Use your notes and past assignments to provide the reason for the classification made.

 

Write PHYSICAL or CHEMICAL next to each change. Give a brief reason for your answer.

Change

Physical or Chemical Change?

Reason

1. burning wood

 

 

2. breaking glass

 

 

3. water evaporating

 

 

4. car battery powers car

 

 

5. the wind blowing

 

 

6. sugar being burned

 

 

7. making ice cubes

 

 

8. grinding steel

 

 

9. dry cleaning clothes

 

 

10. drying clothes

 

 

11. volcano erupting

 

 

12. paint drying

 

 

13. bread making

 

 

14. boiling a potato

 

 

15. dissolving salt

 

 

16. food rotting

 

 

17. cutting paper

 

 

18. a plant growing

 

 

19. rocket engines burning

 

 

20. dry ice in water

 

 

 


Appendix 2.7

Observing and Recording Characteristics of Chemical Reactions

Reference for Unit 2, Task 1.5

 

Introduction: In this activity you will carry out a series of brief experiments. As you perform each experiment, look carefully for clues that indicate whether a chemical reaction has taken place.

Safety Precautions

Use protective equipment as indicated:

·         chemical safety goggles

·         protective clothing

Wash thoroughly after completing lab. Handle all chemicals with care as instructed by the teacher.

Dispose of chemicals and solutions in this lab in a waste disposal jar.

Aim: To carry out a series of experiments and record the observations associated with chemical change.

Apparatus

·         water

·         filter paper

·         ammonium chloride (1 g)

·         bunsen burner

·         test tube

·         watch glass

·         copper(II) sulfate solution

·         funnel

·         iron filings

·         ammonium phosphate solution

·         silver nitrate solution

·         phenolphthalein solution

·         calcium hydroxide solution

·         eye dropper

Method

1.   Obtain 1 g of ammonium chloride. Measure this using a digital scale. Use a piece of paper towel to hold the ammonium chloride sample. Obtain a test tube and add 1.2 cm of water to it. Pour the ammonium chloride into the water and observe and record your observations in regards to sight and touch (outside of test tube). Use the chart that is included in the Observations to record your observations (Chart 1).

2.   Obtain 5 mL of copper(II) sulfate solution. Obtain 2 g of iron filings and place the filings in a funnel with filter paper (as instructed by teacher). Use a retort stand and a ring clamp to set up the funnel over a 250 mL beaker. Pour the copper(II) sulfate solution over the iron filings and observe and record the observations in the chart provided (Chart 1).

3.   Sprinkle a little table salt on a tarnished penny in a watchglass. Add enough vinegar to cover the coin, and let stand one minute. Wash off and dry the penny. Observe and record its appearance. Use the observation chart provided to record the observations (Chart 1).

4.   Obtain a small piece of magnesium ribbon. Light a Bunsen burner according to proper lab procedures and burn the magnesium ribbon using the tongs to hold on to the sample. Do not look directly at burning magnesium. Record your observations in Chart 1.


Appendix 2.7  (Continued)

 

5.   Obtain 1 g of baking soda. Obtain a thumbnail amount of vinegar in a test tube. Put the baking soda into the vinegar. Record your observations in the chart provided (Chart 1).

6.   (Teacher Demonstration) Mix 1 mL of sugar and 1 mL of baking soda together. Heat the mixture in a test tube with a supporting test tube/clamp/retort stand. Record the observations in the chart provided.

7.   Obtain 2 mL of sodium phosphate solution. Place this in a clean test tube. Make sure that the graduated cylinder is rinsed out after this has been done. Record the appearance of the sodium phosphate solution in Chart 2.

9.   Obtain an eye dropper and fill the eye dropper ¼ full with silver nitrate solution. Record the appearance of the silver nitrate in Chart 2.

10.  Add the silver nitrate solution, drop by drop, to the sodium phosphate solution. Record the number of drops required to produce a white precipitate (Chart 2). Dispose of the solutions in a waste disposal jar.

11.  Obtain 2 mL of phenolphthalein solution. Record the appearance of phenolphthalein (Chart 2). Obtain 2 mL of calcium hydroxide solution. Record the appearance of the calcium hydroxide in the chart provided (Chart 2). Add the two together and record the colour of the precipitate formed (Chart 2). Dispose the waste solutions in a waste disposal jar.

 

Observations

 

Chart 1

 

Procedure

Description of Reactants (What you started with)

Observations

Type of Change (Physical or Chemical)

Ammonium chloride + water

 

 

 

Copper(II) sulfate solution + iron filings

 

 

 

Tarnished penny + vinegar + salt

 

 

 

Magnesium ribbon + heat

 

 

 

Baking soda + vinegar

 

 

 

Sugar + Baking Soda + Heat (teacher demonstration)

 

 

 

 


Appendix 2.7  (Continued)

 

Chart 2

Solution

Observations

Sodium phosphate

 

Silver nitrate

 

Sodium phosphate + silver nitrate

 

Phenolphthalein

 

Calcium hydroxide

 

Phenolphthalein + calcium hydroxide

 

 

Conclusions

1.   In which experiments did a new substance appear to be produced? Give reasons for your answers.

 

 

2.   What experiment(s) shows a change in temperature?

 

 

3.   Which experiment(s) showed a change in colour?

 

 

4.   What is a chemical change? State two examples, one in the lab and one from your everyday experience.

 

5.   Describe 5 clues that may indicate a chemical reaction has occurred.

 

 

6.   Classify each of the following as a physical or chemical change. Explain your answer in each case.

a.   making ice cubes

b.   boiling water

c.   drawing a sketch

c.   baking bread

d.   burning coal

e.   cutting bread

7.   What is a precipitate?

 

 

8.   How quickly did the precipitates form in this experiment?

 

 

9.   Identify some of the reactions in this experiment as

a.   decomposition

 

b.   synthesis

 

c.   oxidation


Appendix 2.8

What is A Concept Map?

Reference to Unit 2, Task 1.6

 

Introduction: Concept maps show links between a main concept and a variety of specific sub-concepts known as DESCRIPTORS. Descriptors are then linked to term(s) known as CONNECTORS. Connectors are statements which clearly show the link between the descriptors. Concept maps serve as graphic organizers that are covered in class.

 

Example: Television

 

 

Signal from cable or antenna

 

 

 

 


Appendix 2.9

Chemical Reactions in Everyday Life

Reference for Unit 2, Task 1.6, 3.1; Unit 4, Task 3.3

 

Sample Concept Map – Common Chemical Reactions at Home and at Work

 

 


Appendix 2.10

Concept Map Checklist

Reference for Unit 2, Task 1.6

 

Student:                                                                                                Date:

 

Concept:

 

Organization

 

___      1.         General to specific

 

___      2.         Levels of hierarchy shown

 

___      3.         Branching demonstrated

 

___      4.         No repetition of descriptors

 

___      5.         Propositions used for all linkages

 

___      6.         No linking lines crossed

 

___      7.         Some cross-linkages between concepts shown

 

 

Content

 

___      1.         Relationships between specific descriptors were logical

 

___      2.         Appropriate propositions (linkage words) were used

 

___      3.         Cross linkages were logical

 

___      4.         Isolated specific descriptors and propositions form a sentence

 

 


Appendix 2.11

Reactants and Products in A Chemical Reaction
Cut and Paste Activity

Reference for Unit 2, Task 1.7

 

Arranging Reactants and Products in Proper Order

 

Name:

Date:

 

reactant: (definition) - ____________________________________________________________

product: (definition) - _____________________________________________________________

 

Instructions: In a past lab activity (Observing and Recording Chemical Reactions) six experiments were carried out and observations were made with regards to what was started with (reactants), and what was created from these reactants (products). In this activity the reactants and products from this experiment are mixed up. Cut out the Reactants and Products from this chart and paste them into a new chart in correct order.

 

 

REACTANTS

PRODUCTS

Baking soda + vinegar

Heat + light + magnesium oxide

Copper(II) sulfate (aq) + iron filings (s)

Iron sulfate (aq) + copper (s)

Sugar + baking soda

Shiny penny + salt + vinegar

Tarnished penny + salt + vinegar

Heat + light + gas + sugar/baking soda

Magnesium + oxygen

Ammonium chloride (aq) + water + decrease in temperature

Ammonium chloride(s) + water (aq)

Baking soda (aq) + vinegar + gas

 

 

 

REACTANTS

PRODUCTS